The look of the audio and video players is set by your skin. Skins that offer a choice have a Player Type setting in ACP > Skins > (your skin) > Global Config, in the Players section.
The Elastic 2 skin offers:
Its Players section also has Auto Play, which starts the profile players (Audio, Playlist and Video) automatically.
Choose a player, save, and open a profile with audio or video to see it.
Blue Monday:
Template designers can show a specific player with the {jrCore_media_player} template function. See the Template and Function Reference.